Tetraselmis

Introduction

Tetraselmis is a sizeable genus (more than 50
species) of green flagellates. Most
species are known from inshore marine environments, tidepools in particular, but a few
freshwater species are also known, and some marine invertebrates harbor exo- or endosymbiotic
species. Tetraselmis is an ancestral genus, with many of the morphological features of the
"prasinophyte" grade of basally-derived green plants. Its true phylogenetic position appears to
be near the base of one of the main clades of "chlorophyte" green algae.
Certain species of
Tetraselmis (which may be listed under other names, most often
Platymonas or Prasinocladus), and the closely related genus
Scherffelia, are significant experimental
organisms in cell biology and plant physiology. They featured
prominently in the discovery and
subsequent characterization of the centrin (=caltractin) family
of cytoskeletal proteins. Some species are
also important in aquaculture as food organisms for juvenile fish and shellfish.

Postulated global eukaryote phylogeny based on presence or (ancestral)
absence of mitochondria,
and shape of mitochondrial cristae. Tetraselmis belongs to the
flattened clade.

Postulated phylogenetic position of Tetraselmis, inferred
from molecular and morphological data.
Branch lengths are arbitrary and do not reflect phylogenetic
distance.